docs: def _maybe_deserialize_body(self):
          """Attempt to deserialize the message body based upon the content-type.
  
          :rtype: mixed
  
          """
          if not self.content_type:
              return self._message_body
          ct = headers.parse_content_type(self.content_type)
          key = '{}/{}'.format(ct.content_type, ct.content_subtype)
          if key not in self._SERIALIZATION_MAP:
              if key not in self._IGNORE_TYPES:
                  self.logger.debug('Unsupported content-type: %s',
                                    self.content_type)
              return self._message_body
          elif not self._SERIALIZATION_MAP[key].get('enabled', True):
              self.logger.debug('%s is not enabled in the serialization map',
                                key)
              return self._message_body
          value = self._message_body
          if not self._SERIALIZATION_MAP[key].get('binary'):
              value = self._maybe_decode(
                  self._message_body, ct.parameters.get('charset', 'utf-8'))
          return self._maybe_invoke_serialization(value, 'load', key)